What is Colour?

The fundamentals every professional must understand

As a colour professional, you face complex challenges daily. A brand identity that must be recognisable worldwide, colours that must reproduce consistently from design to end product, or an interior that allows people to function optimally. All these challenges require a deep understanding of what colour truly is – not just conceptually, but practically.

Colour is not a property of objects, but a perceptual phenomenon that arises through the interaction of four essential components: light, darkness, surface and observer [1]. This definition sounds abstract, but has direct practical consequences. Too much light eliminates colour just as effectively as too little light, which explains why every professional colour specification must define lighting conditions.

The three dimensions that determine your daily practice

Hermann Grassmann laid the foundations of modern colour science in the 19th century by defining colour as a three-dimensional phenomenon [2]. These three dimensions – lightness, chroma and hue – still form the basis of all professional colour ordering systems you use daily.

Lightness not only determines the visibility of colours, but has direct consequences for functionality. Dark colours absorb more light, which becomes problematic in outdoor applications due to thermal expansion [3]. In safety applications, high lightness values ensure better reflection and visibility.

Chroma, the degree of saturation, drives emotional response and brand recognition. Highly saturated colours attract maximum attention – essential for retail and marketing. Colours with low saturation appear more professional and neutral, suitable for corporate environments where authority and reliability are central.

Hue forms the basis for all colour harmony theories and brand identity systems. Different sectors have developed specific hue associations: certain tints are associated with flavours and quality perception in the food industry, while technology applications optimise interface colours for user experience.